Ensure that the ACK from the last information transfer phase has been

de-asserted by the initiator before changing phase or releasing the bus.
Corrects a SCSI specification violation in target mode.

1 files changed, 16 insertions, 2 deletions

diff --git a/sys/dev/aic7xxx/aic7xxx.seq b/sys/dev/aic7xxx/aic7xxx.seq
index 3377449..5abe1b6 100644
--- a/sys/dev/aic7xxx/aic7xxx.seq
+++ b/sys/dev/aic7xxx/aic7xxx.seq
@@ -32,7 +32,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: aic7xxx.seq,v 1.83 1998/12/17 00:06:52 gibbs Exp $
+ *	$Id: aic7xxx.seq,v 1.84 1999/01/14 06:14:15 gibbs Exp $
  */
 
 #include <dev/aic7xxx/aic7xxx.reg>
@@ -485,6 +485,9 @@ target_disconnect:
 		mvi	MSG_SAVEDATAPOINTER call target_outb;
 		mvi	MSG_DISCONNECT call target_outb;
 
+target_busfree_wait:
+		/* Wait for preceeding I/O session to complete. */
+		test	SCSISIGI, ACKI jnz .;
 target_busfree:
 		clr	SCSISIGO;
 		call	complete_target_cmd;
@@ -554,7 +557,7 @@ target_sphase:
 		mvi	SCSISIGO, P_MESGIN|BSYO;
 		/* MSG_CMDCMPLT is 0, but we can't do an immediate of 0 */
 		mov	ALLZEROS call target_outb;
-		jmp	target_busfree;
+		jmp	target_busfree_wait;
 	
 complete_target_cmd:
 		test	SEQ_FLAGS, TARG_CMD_PENDING	jnz . + 2;
@@ -1345,9 +1348,20 @@ if ((ahc->flags & AHC_TARGETMODE) != 0) {
  * from out to in, wait an additional data release delay before continuing.
  */
 change_phase:
+	/* Wait for preceeding I/O session to complete. */
+	test	SCSISIGI, ACKI jnz .;
+
+	/* Change the phase */
 	and	DINDEX, IOI, SCSISIGI;
 	mov	SCSISIGO, SINDEX;
 	and	A, IOI, SINDEX;
+
+	/*
+	 * If the data direction has changed, from
+	 * out (initiator driving) to in (target driving),
+	 * we must waitat least a data release delay plus
+	 * the normal bus settle delay. [SCSI III SPI 10.11.0]
+	 */
 	cmp 	DINDEX, A je change_phase_wait;
 	test	SINDEX, IOI jz change_phase_wait;
 	call	change_phase_wait;